In the past, utility vehicles have used an articulated frame to improve maneuverability and ease of operation. With vehicles such as asphalt compactors, it is desirable to allow the operator to selectively, laterally offset the rear roller drum from the front roller drum. This is useful in situations such as when the operator wishes to run the front drum next to a curb and the rear drum several inches away from the curb when compacting an asphalt roadway so that the operator need only be concerned about the position of the front drum. This reduces the risk that the rear drum will inadvertently ride up onto and crack the curb, requiring expensive repair of the curb.
Being able to laterally offset the front and rear drums also helps the operator keep the rear drum away from an adjacent curb or wall when the vehicle is being turned. When an articulated vehicle such as an asphalt compactor turns away from an obstruction, the rear half of the frame momentarily moves towards the obstruction. If the rear drum is offset by several inches, the risk of the rear drum contacting the obstruction is greatly reduced.
While some prior art asphalt compactors have used frames with a single articulation joint and a mechanism to laterally offset the front and rear frame portions at the articulation joint, the designs have not produced optimal performance and result in an undesirably large increase in the overall length of the compactor. Of course, increasing the length of the compactor decreases the compactor's maneuverability and ease of operation.
It will therefore be appreciated that there has long been a significant need for an articulated utility vehicle with improved maneuverability and ease of operation. Preferably, the articulation joint will also provide for lateral offsetting of the front and rear frame portions. The utility vehicle should use an articulated joint design that minimizes the spacing required between the front and rear frame portions so as to reduce the overall length of the vehicle compared to articulated vehicles using prior art articulation joints which provide lateral offsetting. The present invention fulfills these needs and further provides other related advantages.